No abstract

HE blue color of solutions of metals in liquid ammonia and alkyl amines has been observed and several of their physical properties have been investigated by Kraus and others. In order to account for the electrical properties of these solutions Kraus' assumes that in all cases the metal dissociates on dissolving according to the equationwhere Me+ is the cation present in solutions of salts of the metal and 6 is an electron. Both Me+ and 8 may be combined to a greater or less extent with the solvent molecules. From measurements of the electromotive force of concentration cells Kraus' concludes that at least one third of the current in a normal solution of sodium is carried by the unsolvated electron.The color of these metallic solutions appears to be independent of the metal and the solvent used. They are intensely blue to transmitted light, and, as far as the eye can judge, the shade of color is the same in all cases. In daylight .oox normal solutions of potassium and sodium in ammonia can be matched against ammoniacal copper solutions. This is also true of a saturated solution of magnesium in liquid ammonia.Similar blue solutions are obtained when sodium is dissolved in molten sodamide' and when calcium is dissolved in a molten mixture of potassium and sodium chloride. 'The blue color of these metallic solutions may be due (a) to un-ionized molecules (or atoms) of the metal, (b) to solvated electrons, (c) to unsolvated electrons.(a) We should expect the color of the un-ionized metal atoms to vary with the metal and to be similar to that of the vapor of the metal, provided the metal atoms were not affected by the presence of the solvent. ' J. Am. Chem. Soc., zg, Igs7 (I9o7). ' J. Am. Chem. Soc., g6, 864 (I9I4).Titherley, J. Chem. Soc., 6g, So8 (I894).' A description of this experiment wi11 be published shortly. 34 G. Z. GIBSON AND 8". J. ARGO. t SECOND SERIES+Sodium vapor has a purple color. The absorption spectrum. of the vapor, however, has been investigated by Wood and others, and is in no way similar to that of the solution in ammonia.

Fluorine was first prepared in quantity by H. Moissan2 by the electrolysis of anhydrous hydrofluoric acid rendered conducting by the addition of potassium hydrogen fluoride. Moissan began with a platinum U-tube as his electrolyzing vessel, the openings in which were closed with fluorite stoppers in which the electrodes of platinum-iridium were set. Later he found that copper would serve equally well as an electrolyzing vessel but that platinum electrodes must be used, Fig, I. With copper electrodes, polarization took place due

The method used by Lewis and Kraus, and Lewis and Keyes for the determination of the electrode potential of sodium,4 potassium6 and 1